Choosing a beautiful diamond involves narrowing down your shape and selecting high-quality options for the 4Cs — without overpaying. You’ll then compare individual diamonds to see which one offers you the most brilliance and fire. Follow our step-by-step guide below to find a stunning diamond while staying within your budget. Budgets can vary a lot from one person to another, so make sure you’re comfortable with the money you want to spend (for example, if your budget is around 4k, hop in our $4000 engagement ring article after you read this 9 step guide to get inspired).

We recommend reputable online diamond vendors. Based on our years of experience, James Allen and Blue Nile have proven to offer the best selection at the best prices (see the full list of Best Online Jewelry Stores here). Because their overhead costs are low and they don’t keep an inventory in-house, you’ll find the best deal with these two vendors. Both James Allen and Blue Nile provide HD and 360° imagery so you can compare diamonds up-close before purchase.


1. Choose Your Diamond Shape

The shape of your diamond is the launching point of your ring’s design. No shape is better than the other—it’s up to your personal preference (or your partner’s). Round Brilliants are the most popular diamond shape for engagement rings and give off the most brilliance. Others prefer a more unique shape like a Cushion Cut or an Oval. If you’re unsure what your partner prefers, you can ask her family and friends.

Select a shape to narrow down your search and compare diamonds.

Choosing a diamond shape on Blue Nile
Choosing a diamond shape on James Allen

2. Select Your Carat Weight

Is your fiance-to-be expecting a 1 or 2 carat diamond? Are you looking for a stone that’s noticeable but not over the top? Choose the carat weight range you’re open to considering, such as a 0.95 to a 1.08 Carat diamond. As carat weight increases, so does the price.

Carat weight impacts how large a diamond looks (as does its shape and cut quality). Learn about the average diamond size people buy to help you decide.

3. Narrow Down on Cut Quality

The aspect that most greatly impacts a diamond’s beauty is its cut quality. Cut grades aren’t standardized across all vendors, but in general, we recommend only Excellent and Ideal cut diamonds.

For example, on Blue Nile’s site for round diamonds, you should limit your selection to Ideal and Astor Ideal diamonds. On James Allen, choose Ideal and True Hearts cut.